Issue #3134371 by dsnopek: Allow changing the layout of an existing section in Layout Builder UI

(cherry picked from commit bf5c669e)

Closes #3134371

core/modules/layout_builder/css/layout-builder.css

@@ -58,6 +58,10 @@
   background-color: #ffd;
 }
 
+.layout-builder__section .layout-builder__section_links a.layout-builder__link:not(:first-child, :last-child)::after {
+  content: " | ";
+}
+
 .layout-builder__region {
   outline: 2px dashed #2f91da;
 }
@@ -178,3 +182,34 @@
 .layout-builder-components-table .tabledrag-changed-warning {
   display: none !important;
 }
+
+.layout_builder__region-mapping__toggle-wrapper {
+  text-align: right;
+}
+
+[dir="rtl"] .layout_builder__region-mapping__toggle-wrapper {
+  text-align: left;
+}
+
+#drupal-off-canvas-wrapper .layout-builder__region-mapping {
+  margin-top: 0.625rem;
+}
+
+#drupal-off-canvas-wrapper .layout-builder__region-mapping__region {
+  margin-bottom: 1.5em;
+  padding-bottom: 1.5em;
+  text-align: center;
+  outline: 2px dashed #979797;
+}
+
+.layout-builder__region-mapping__region-label {
+  margin-bottom: 0.5em;
+}
+
+#drupal-off-canvas-wrapper .layout-builder__region-mapping__block {
+  margin: 0.5em;
+  padding: 0.5em;
+  cursor: move;
+  border: 2px solid #333;
+  font-size: 1.5em;
+}